The lecture on nuclear reactions is presented in two parts. Nuclear reaction notation is introduced. The role of energetics in nuclear reactions is discussed and evaluated, including Q value, reaction barriers, and threshold energy. Center of mass and laboratory frames are discussed. The different processes involved in the formation of isotopes is provided including photonuclear processes. Reaction energetics, mechanisms and types are described. Nuclear reaction cross sections are described, with a presentation on values and limits given. This includes role of angular momentum in cross section values. The stellar production of elements is presented in terms of nuclear reactions. These provide the basis for understanding the formation of isotopes in stars.
Hi class. I have some questions regarding quiz 9. Do we use Lab Threshold at all? Do we need to calculate the laboratory frame when calculating for the Coulomb barrier? When we provide the notation for the formation of stable gold, how many products will there be?
ReplyDeleteDaniel
ReplyDeleteFrom you quiz you understand what is needed for the reaction calculations. The equations are presented in lecture. The threshold reaction incorporates the change from center of mass to laboratory.
For the notation please consider this example.
Provide the reaction of 18O on 248Cm to make 261Rf with 5 neutrons in nuclear notation
248Cm(18O,5n)261Rf
Thank you for posting this further elaboration on this, it did aid me in looking at the problem differently to see my error in my calculation I think.
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ReplyDeleteGood lecture, the section on stellar nucleosynthesis was very interesting. I had wondered which fusion reactions were involved in getting the stars from H to Fe.
ReplyDeleteI did have some confusion on the compound nucleus on the quiz and how to obtain said nucleus. The 3rd link - Nuclear Reaction Energetics (http://jol.liljenzin.se/KAPITEL/CH12NY3.PDF) on the lecture notes page helped clarify this, section 12.7 in that pdf to be exact.
thanks for the comment on fusion. For the nuclear reaction make sure you balance the number of nucleons.
ReplyDeleteThis was an interesting lecture. I was glad to learn more about reactions along with having a thorough explanation about synthesis of different element groups. The explanation on calculating values with other factors, such as mass excess, that must be considered in order to accurately calculate threshold energy.
ReplyDeletethanks for the comments.
DeleteI enjoyed this lecture. The examples provided regarding the reaction barrier were very helpful and the part of the lecture that covered nucleosynthesis was interesting.
ReplyDeleteThanks for the comments regarding examples
DeleteThis lecture was great and very interesting as always. Seeing a different way to calculate the Q value through the use of the kinetic energy and angle was great information to learn.
ReplyDeleteThere are a few different ways to evaluate energetics. This is another example.
DeleteGood lecture and interesting topic. I enjoyed learning about stellar nucleosynthesis and the formation of elements.
ReplyDeleteI enjoy the nucleosynthesis also.
DeleteThis lecture was interesting. The examples in the lecture and the comment in the blog were helpful for this PDF quiz.
ReplyDeletethanks for the comment and reference to the blog.
DeleteThank you for the interesting lecture and the clarification of the notation. Looking at the powerpoint alone, I couldn't quite figure that out.
ReplyDeletethanks for the comments
DeleteThanks for the clarification to the second comment. It helped a lot with the pdf quiz.
ReplyDeletethanks for the comment and quiz submission
DeleteI was also thankful the clarification.
ReplyDeleteLooking back at this lecture, I found meaningful the way we write nuclear reactions because it shows how the target changes into the daughter. Another interesting part of this lecture was stellar nucleosynthesis because once the fussion occurs the temperature increases and the pressure drops.
ReplyDeleteI forgot to post on some of these lectures! Sorry. I was very confused about the reaction notation, as well. The office hours prior to the Quiz were very helpful, though, and I think I understand this concept perfectly fine now. Thanks!
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